how to check admin is logged in or not in Magento

 Hi with the below peace of code you can check admin user is logged in or not anywhere is magento

$sesId = isset($_COOKIE['adminhtml']) ? $_COOKIE['adminhtml'] : false ;
$session = false;
if($sesId){
    $session = Mage::getSingleton('core/resource_session')->read($sesId);
}
$loggedIn = false;
if($session)
{
    if(stristr($session,'Mage_Admin_Model_User'))
    {
        $loggedIn = true;
    }
}
var_dump($loggedIn);// this will be true if admin logged in and false if not